


Teacher's Pet

by Saiyurimai



Category: Undertale (Video Game)
Genre: Alternate Universe - College/University, Alternate Universe - Student/Teacher, Angst, F/M, Fluff and Smut, Gen, M/M, Multi, NSFW, Original Character(s), Polyamorous Character, Polyamory, Professor Edge, Professor Gaster, Professor Stretch, Seriously there's a ton of it in here eventually, Sex, Sexy Times, Soul Sex, Taboo, Teacher-Student Relationship, Threesome, all the sex, lemony fresh, p in v, soul mates
Language: English
Status: Completed
Published: 2019-04-30
Updated: 2019-05-02
Packaged: 2020-02-10 13:45:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,591
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18661606
Author URL: https://archiveofourown.org/users/Saiyurimai/pseuds/Saiyurimai
Summary: Sai, Bucky and Lines are college students, each facing multiple challenges as they go through the daily struggles of being a college student. Only making it worse is their highly attractive teachers.





	1. Chapter 1

Sai rolled out of bed with a groan, hitting her alarm as she glared over at the digital reading angrily. She was not at all a morning person. “Come on or you’ll be late for class again Sai.” Came her room mate’s voice, a travel mug of what was most definitely coffee placed in her field of view. Sai groaned and rubbed her face.

 

 

“I literally hate all of this…” She groaned and sat up finally, taking a sip as her room mate grabbed her things, placing her laptop in her bag. “How is it that you’re up so much earlier than me all the time Bucky? And how do you have time to make coffee?” She asked, sipping at her coffee while Bucky shrugged, continuing to packing her things to get ready to go.

 

 

“Because I didn’t spend my night binge watching crime shows all night. Maybe next time you should go to bed on time.” Bucky teased, hiding a yawn herself as she finished packing, looking at her watch. “But I gotta go, I’ll see you later for lunch though right?” She asked and Sai nodded with a yawn of her own, waving her off as Bucky hurried out the door to get to her first class.

 

 

Sai started to get dressed and get her things ready, always just this side of late. But she was going to be starting a new class today. Something she wanted to challenge herself, an introduction to physics just for fun. But she was already going to be a couple minutes late if she didn’t get her butt in gear and start heading towards her class. She grabbed her things, brushed her hair and threw it up into a messy bun before quickly heading out of the dorm, careful to lock it up. Didn’t need anyone coming in and trying to mess with their things.

 

 

She grabbed a granola bar out of her bag as she hurried down the halls, forgoing the elevator and rushing down the stairs, skipping several steps as she went to run across campus to get to the science building which was far across the other side. She booked it as fast as she could, avoiding other classmates and teachers as she went. She groaned inwardly as she saw the door to the classroom was closed already. Well, better late than never she supposed as she steeled herself and tried to sneak into the classroom hearing the class go silent as soon as she opened the door.

 

 

“Well. Excuse me class. It appears we have a late comer in our midst. I do sincerely hope that you have a good excuse for disrupting my lecture.” Sai winced and turned towards the deep English accented voice, her face blushing faintly as she craned her neck to look up at her professor. Holy crap he was tall, and oh so cute. Sexy actually, dressed in his grey turtle neck, black slacks, his skeletal visiage staring her down as she gulped nervously. His violet eye lights were looking her up and down, judging, making her want to slink away.

 

 

“Uh…I got uh…I got lost.” She offered lamely hoping to get him off her case as quickly as humanly possible, because this right here made her want to just run away with her tail between her legs. The professor narrowed his gaze and stared at her a little longer before humming in thought, pulling away and pointing a long finger towards an empty seat towards the front of the class. Crap. Now she really couldn’t just slink away into the shadows of the lecture room.

 

 

“I expect you to be here on time, every time. You will not interrupt my lectures. You will not disrupt my classroom in any shape or form. You should take notes on everything, it is all important and if you do not show up to my class tomorrow on time Miss Mai, you will be locked out and failed automatically. Is that understood?” He had moved over to his desk in front of the large white board where several complex equations were written up over it in elegant but clear handwriting. Sai nodded and took her seat, feeling like a chided child as she opened up her laptop and set it to record the lecture, taking out her notes and getting to work. She truly never wanted to feel like that ever again. But the way his eye lights had traveled over her, lingering on her lips, chest and hips? Had her feeling some type of way.

 

 

Bucky hurried to class, headphones in and listening to her playlist. She hoped that she would make it on time to class, she hated being late. Part of her hoped that Sai was up and already up and hurrying to class but the other part knew that her roommate would be rushing all the way to the last possible second. But that wasn’t her problem, she made the coffee at least. Sai could charm the pants off of anyone if she really wanted to, she’d be fine. Bucky cursed under her breath as she noticed the time and picked up her pace. She clutched her things to her chest and hurried down the halls to her English course. There were a few people milling around the entrance but she managed to slink through a gap and pulled her headphones out as she found a spot for her to set up shop off in a corner somewhere.

 

 

She opened up her laptop, got it ready as her class mates filed in, most of them laughing at some joke while she kept to herself. She sometimes wished that Sai or Lines had this class with her but…oh well she supposed. She could handle it. She leaned back and waited as the class finished filing in but there still wasn’t any show from the professor. There were mumblings from some of the other students until finally a skeleton monster popped into existence in the chair at the small desk in the front of the class.

 

 

Bucky fought the urge to squeak in surprise as she looked to the front of the class, her “professor” yawning and putting his feet up on the desk. “Name’s Papyrus, this is….Uhhh…English right? Yeah. English something. But since there’s so many other Papyrus’s you lot can call me Professor Stretch. So long as you show up on time, do the assignments y’all should be fine.” He had a nice southern drawl that brought a soft smile to Bucky’s lips before she even realized it. She started her recording program as Professor Stretch started his lackadaisical lecture about what to expect over the next few months. It was so easy to just relax, listen to his easy going nature as he spoke, he made jokes, mostly puns that had the whole class chuckling more than once.

 

 

It was insane how quickly an hour and a half lecture went listening to him talk back and forth with the rest of the class, so much so that when it was over it was like a dream popping, bringing her back to reality. He dismissed the class and popped out of existence in the blink of an eye. Must be nice to travel like that. Seemed so easy. Bucky packed up her things and hurried on to her next class, her mind kept going back to her English professor though even in her other classes she kept thinking back on that easy drawl.

 

 

By the time lunch rolled around she was surprisingly not the first one to be at the usual table. Lines sat there flipping through one of her text books and nibbling absentmindedly on her lunch. “Hey, where’s Sai?” She asked as she set her own things down on the table, making herself comfortable as Lines looked up with a smile in greeting.

 

 

“She’s in the lunch line. She should be here in a sec though I think. How’s it going?” Lines asked, putting away her textbook and focusing on her friend while Bucky sighed and told her about her day, Sai showing up a few minutes later, looking as put together as Sai usually was which was not at all, but somehow she managed to pull it off. Bucky and Lines shared a look and laughed as Sai made herself comfortable at the table. The three of them caught up, Bucky listening to Sai gush about her hard ass physics teacher, Lines describing the intimidating and frankly scary sounding business professor before talking about her own English professor. “I’ve heard that Dr. Gaster is absolutely brutal when it comes to testing. You sure you’re up for that?” Lines asked and Sai shrugged, taking a bite of her sandwich.

 

 

“I don’t care. It isn’t really part of my degree to be honest so it isn’t going to affect it. I figured I would challenge myself a bit anyways. Who knows, maybe I can just get a little extra credit.” Sai winked with a laugh both Bucky and Lines shaking their heads at her. “What? You know you totally would do it too. I had Stretch last term for English. The guy is cute, not really my type but he’s cute.” Bucky flushed at Sai’s side eye and cleared her throat, taking a drink of her coffee.

 

 

“Oh my god Sai. Please. You know the rules about dating professors and students. It’s like the biggest no no. It’s in the handbooks!” Lines eyed her friend as Sai shrugged nonchalantly. For someone who was always claiming to not care about the rules Bucky knew that Sai was all bark and no bite. She followed them just as much as the rest of them did. The three of them continued to eat and talk through their lunch when Lines pointed out the new addition to the lunch area, a fancy new coffee shop that would be opening up soon.

 

 

“Oh man wouldn’t that be nice. It’ll probably be too expensive for us students unless they give us some sort of student discount. Plus you wouldn’t have to worry about making us coffee every morning Bucky.” Sai smiled and Bucky laughed shaking her head. It sure would be nice to get a break every now and again.

 

 

“Haha! And then why would you want to keep little ole’ me around?” Bucky laughed and Sai snorted, shaking her head and looking at her phone. 

 

 

“Because you’re my best friend and you are amazing and I love you but I am gonna be late again to my next class so I will see you ladies later! Love you!” Bucky and Lines watched as Sai hurried off, dropping off her tray and rushing to her next class. Lines shook her head and gathered her things as well, starting to pack up to head to her next class.

 

 

“One of these days she’ll figure out how to get to class without running around like a chicken with her head cut off. Are we going to meet up later to do some studying? I got a test coming up and could really use the help.” Lines asked and Bucky nodded, waving as her friend left before she too got up and headed off to her next class. Seeing Sai sprinting the other direction with a look of panic from the window. Some things will never change she supposed as she settled in for class.


	2. Chapter 2

Lines sighed and walked into the library, heading directly into the business section, to pick up a book for her next class. Her professor was insanely difficult and she was sure that he was trying to drive all of his students insane by the sheer amount of work he was shoving onto them. She was on track and her grades were good but still. He didn’t have to be so crazy intense about it all the time. There was hushed giggling somewhere in the back of the stacks and she rolled her eyes. It was pretty common for couples to try and hook up back in the lesser used section of the library, especially in the darkened areas where there was less foot traffic.

 

 

Lines grabbed the book she was looking for and headed out of the business section, going to the receptionist to check out the book before heading out towards her business class. She saw Bucky leaving her class and gave a wave and a smile as they passed one another in the busy hall. Lines turned down a hall and caught sight of the tall intimidating skeleton with his arms crossed firmly over his chest. One of his sockets was cracked, small scars over some of his bones where a person could see them.

 

 

It spoke of a harsher period in his life that made Lines curious. She’d heard some of the other students theorizing about his past but to be honest each was more outlandish than the last. “Good afternoon Sir.” She greeted him as she passed, not seeing the way his crimson eye lights followed her into the classroom, nor did she see the way the edge of his sharp toothed smile tugged into a subtle grin. She took her seat and settled in for the unbearably long class. By the end of it she knew she wasn’t the only one with a headache as they tried to absorb the information delivered to them.

 

 

“Miss Lines. Stay behind a moment.” The professor called from the front of the class, making several students look her way with pity as she nodded and grabbed her things moving to his podium as he collected his folders into his briefcase. When all the others had filed out of the class it left only the two of them, Lines feeling a bit like a mouse trapped under the gaze of a hunting cat he spoke again. “You do fairly well in my class despite it being incredibly difficult. I have found that I’m impressed by your skills. I am in need of an assistant, to help me grade papers and such. Is this something that would interest you or is it too difficult a task?” He quirked a brow at her as if challenging her to back down from him.

 

 

Lines was certainly not the type to back down though, not from anyone, not even one of the most terrifying teachers on campus. “Is it a paid position sir?” She asked sounding a little more confident than she felt. Professor Edge chuckled and nodded, seemingly impressed with her tone. “Then I’ll accept. Thank you, sir. I appreciate the opportunity.” He hummed in thought and handed her a small pile of papers and a grading key.

 

 

“Good. I want them all done according to the instructions listed. And back on my desk bright and early tomorrow morning. If I catch you sharing these answers with anyone I will not hesitate to destroy every last bit of your college career and any future career you might have regardless of what it is. Is that understood?” Lines nodded, hugging the papers to her chest protectively. She wasn’t a cheater regardless but still. He seemed like he would make good on his threats if she wasn’t careful. 

 

 

“Thank you sir. I understand. Have a good day.” She smiled up at him politely before hurrying out of the classroom, not noticing the way Professor Edge stared after her retreating form.

 

 

Sai flopped back on her bed, careful not to hit the wall as she sighed in frustration. She was halfway through some of the worst homework in her life. Professor Gaster was really coming down on her hard. Every question he called on her, even though she wouldn’t put her hand up to answer, if there was something wrong on the quizzes he brought her up to the front of the class to fail miserably at trying to solve it all the while knowing that he knew that she knew she didn’t have a clue as to what she was doing.

 

 

She was pretty sure he was punishing her for her being late that first time in class and hoped that at some point he would let up but the other part of her actually enjoyed when he would come up behind her, grab the marker from her hand, his long fingers brushing hers ever so slightly. It sent a jolt of electricity through her every single time. The way he would make her stand close to him while he explained step by step how to solve the equations. In a crazy round about way she was actually doing fairly well, better than she thought she would.

 

 

Sai heard Bucky come in and toss her things onto the bed across from her. “Yo, don’t sit. I need coffee. I heard the new coffee place opened up yesterday and I really wanna try it out. My treat.” Sai offered, knowing that Bucky couldn’t possibly turn down a cup of coffee, especially one that she didn’t have to make or pay for.

 

 

“Deal. Gaster making you want to tear your hair out again?” Bucky asked as Sai sat up and put her shoes on, grabbing her wallet and double checking her cash situation. Sai nodded and sighed with frustration. 

 

 

“Yeah. You could say that. He wants another five page paper by Thursday. With a cover page and like six references not including the texts. I have…” She looked at her computer and rolled her eyes, “A page and a half right now.” Bucky shared a look of pity with her friend as Sai got up and took her arm. “So I’m gonna need me some caffeine if I’m ever going to get it done tonight and tomorrow. Like probably a gallon’s worth.” The two laughed and headed towards the new coffee shop, Lines still in class otherwise they’d have invited her to go along with.

 

 

As expected there was a bit of a line but since neither of them had any more classes to go to for the afternoon a little wait didn’t hurt either of them as they caught up and talked about things going on in their lives. Sai and Bucky had similar schedules but there were days where despite sharing a room they didn’t really see each other all that much. Little by little they started to make their way to the front of the line, hearing the whispers, one of which caught Sai’s ear. “Oh my god he is literally so hot…like absolutely smoking…” One girl giggled to her friends who all seemed to agree as they walked past Bucky and Sai.

 

 

Before she can say something to Bucky she sees just what had all the girls giggling. “Hello, what can I get for you cher?” The flame elemental rumbled with a heavy New Orleans accent, looking Sai over the edge of his stylish black glasses. Hot was an understatement Sai thought, her mouth forgetting how to word properly. Luckily Bucky seemed unfazed by the monster and gave her usual order as well as her own. “Sounds good, take a number cher, bring it right out for ya.” He winked at Sai and Bucky guided her to a table with their order number on the table.

 

 

“Earth to Sai? Did you forget how to be a human for a second or what?” She asked as Sai tried to figure out how to function again. Sai shook her head and was finally able to put words together again as she blushed and cleared her throat making Bucky laugh softly. “Uh huh. Alright, reboot, come on. You can do it.” 

 

 

Sai rolled her eyes and leaned back in her chair. “Oh hush it. I was caught off guard okay? It isn’t like I’ve ever seen a literal man made of fire before.” She muttered which made Bucky snicker, glancing up as said fire man came up to the table and placed their orders in front of them. Sai looking up at him and fascinated by the way his flames crackled and flickered. “Are you like solid or would my hand go through you like real flames?” She spilled out without thinking, blushing brightly and sputtering out an apology.

 

 

The flame elemental only chuckled and held out his hand for her to touch. “I assure you, I’m very solid cher. Go ahead, I won’t burn ya. Promise.” Sai hesitated and reached out to touch his hand, surprised by the fact that it was in fact solid and that the flames were warm but didn’t burn her skin. In fact they kind of tickled her palm. “See? Solid.” He chuckled and Sai blushed taking her hand back and hiding her face behind her cup of coffee, thanking him with a mumble. “Bon appetit mon Cherie.” He winked and headed back to behind the counter, Sai watching him go and nibbling on her lip.

 

 

“Like a moth to literal flame I swear to god.” Bucky teased and Sai blushed brighter, trying not to be super obvious. “His name is Grillby by the way. In case you didn’t bother to read his name tag and looking at him like a piece of meat.” Sai rolled her eyes and glanced over his direction and caught his eye, seeing him throw a grin and a wink her direction. Oh she was in trouble. She knew then just where she was going to be getting her coffee fix from now on, she didn’t care just how much it was going to cost.


End file.
